Quantum gravitational decoherence of a mechanical oscillator from spacetime fluctuations

TL;DR

This paper investigates how spacetime fluctuations, modeled via deformed commutation relations or fluctuating metrics, induce decoherence in mechanical oscillators, providing experimental bounds on quantum gravity parameters.

Contribution

It introduces a model linking spacetime fluctuations to decoherence in mechanical systems and derives experimental bounds on quantum gravity parameters from existing data.

Findings

Decoherence occurs in the momentum basis due to spacetime fluctuations.

Experimental data constrains parameters of the quantum gravity model.

Bounds are also applicable to other phenomenological quantum gravity models.

Abstract

We consider the scenario of a fluctuating spacetime due to a deformed commutation relation with a fluctuating deformation parameter, or to a fluctuating metric tensor. By computing the resulting dynamics and averaging over these fluctuations, we find that a system experiences a decoherence in the momentum basis. We studied the predictions of the model for a free particle and an harmonic oscillator. Using experimental data taken from a mechanical oscillator prepared in quantum states of motion, we put a bound on the free parameters of the considered model. In addition, we comment on how these measurements can also provide bounds to other phenomenological quantum gravity models, such as the length scale for nonlocal dynamics.